Fullerene-metalloporphyrin co-crystal as efficient oxygen reduction reaction electrocatalyst precursor for Zn-air batteries

Fullerene-derived carbon materials are promising ORR catalysts due to the intrinsic defects in the carbon cage. Moreover, the N species and metallic catalytic sites can effectively overcome sluggish kinetics caused by the challenge in O₂ activation. In this work, a rod morphology tetraphenyl porphyrin cobalt/C₆₀ co-crystal (CoTPP/C₆₀) was self-assembled and then annealed to prepare a series of N, Co-codoped carbon materials (CoTPP/C₆₀-X). CoTPP/C₆₀-800 obtained at 800°C demonstrates a half-wave potential of 0.824 V_RHE, along with outstanding stability and remarkable methanol tolerance. The superior ORR performance of CoTPP/C₆₀-800 can be attributed to the abundance of defects, appropriate nitrogen (N) species (pyridine-N, graphitic-N), Co-Nx sites, and Co nanoparticles. Moreover, the zinc-air battery assembled with CoTPP/C₆₀-800 as a cathode demonstrated a high-power density of 111.7 mW cm^-2. This work provides a new strategy for designing and synthesizing advanced ORR catalysts for Zn-air batteries.